Oil-cooled transformer.



F. G. GREEN. OIL GOOLED TRANSFORMER. urmounon FILED APR. 23, 1910. mmnwnn 00w. 2, 1m.

Patented Nov. 11, 1913.

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Inventor y Hns Jlttorneg.

Witnesses:

F. 'c. GREEN.

OIL OOOLED TRANSFORMER.

APPLIOATION FILED APB. 23,1910. RENEWED OUT. 2, 1912.

1,078,141 Patented Nov. 11, 1913.

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M Frank C. reef].

' M M r '3 His Jlttorngy.

F. G. GREEN.

OIL GOOLED TRANSFORMER.

rum-r1011 rum) APR. 23, 19 0. RENEWED 001.2, 1912.

1,078,141, Patented Nov. 11, 1913.

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Wlfinesse Inventor" f 2pm FranK OGreen,

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His Attorney.

FRANK C. GREEN, E

PITTSFIELD, MASSACHUSETTS, ASSIGNOE TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

OIL-COOLED TRANSFORMER.

Specification of Letters Patent.

Patented Novel 1, 1913.

a I; continuation of application Serial No. 539,647, filed January 24, 1910. This application filed April 23, 1910,

e 9 Serial No. 557,244. Renewed October 2, 1912. Serial No. 723,588.

I To all whom it may concern:

Be. it known that I, FRANK C. GREEN, a citizen of the United States, residing at Pit-tsfield, county of Berkshire, State of Massachusetts, have invented certain new and useful Improvements .in Oil-Cooled Transformers, of which the following is a specification.

This invention relates particularly to means for cooling electric transformers by the so-called forced oil system, and one of its objects is to provide a compact and efiicient device uniting. in'onc structure the transformer tank and the cooler with the mechanism for effecting a positive circulation of the oil. As usually built, the cooler is a separate piece of apparatus, connected with the transformer tank by a system of piping, all of which occupies valuable room and isliable to give rise to trouble on account of leaks. In my invention, the cooling com 'artment is arranged outside of and surroun ing the transformer casing, and the circulating pump is mounted on the top of the transformer, so that the piping is as short as possible. Provision is made, also, for a natural circulation of the oil.

This application is a continuation of my previous application, Serial No. 539,647,

led January 24, 1910.

In the accompanying drawings, Fi are 1 is a perspective view of my improve combined transformer and cooler; Fig. 2 is a sectional elevation of the same; Fig. 3 is a similar section on a plane at right angles to that of Fig. 2; and Fig. 4 is a vertical section ona larger scale, showing the arrangement of the coils and core of the transformer.

I have shown my invention as embodied in a three-phase transformer of standard design. The arrangement of the core and coils is in general similar to that shown in "Patent No. 713,327, W. S. Moody, trans- ,former, the incombustible barriers being omitted.

The transformer core 1 is clamped between top and bottom plates 2, 3, the bottom plate having legs 4 which stand upon ledges 5\in the basin-shaped base 6. A sheet metal casing 7 fits upon the top of the plate 2 and rises to a point above the level of the oil. Surrounding the coils and this inner casing is an outer casing 8 which rests upon ledges 9 of the base and rises to a. point above the level of the oil; being set as close to the coils as possible, butneccssarily leaving some s ace between itself and the inner casing The transformer" tank proper incloses the outer casing 8, with a considerable space between them, the lower end of the body 10 being riveted to the base by a liquid-tight joint.

In the lower end of the outer casing 8, and preferably on the high tension side of the transformer, are one or'more openings 11 which permit the oil to pass freely from the space outside of said casing to the in side thereof. Mounted on the top 12 of the transformer is a pump, preferably a centrifugal pump 13, driven by an electric motor 14. The suction pipe 15 of this pump terminates at 16, inside the inner casing 7 and somewhat below the level of the oil which is shown in dotted lines in Figs. 2 and 3, while its delivery pipe 17 opens into the space between the outer casing and'the tank body at'or near the level of the oil. Both these pipes are referah-ly on the low tension side. Fig. 4' siiows the arrangement of the ventilating ducts for circulating the oil through the coils and adjacent to the core. The coils 25 are, arranged in three groups, each for one phase, and each group is surrounded by an insulating casing 26. Between the primary and secondary coils of each grou are inserted insulating members 27. T e coils are spaced apart as shown in the drawing, so that ventilating ducts 28 are formed between the coils, ventilating ducts 29 between the coils and the insulating casing, and ventilating ducts 30 between the insulating casing and the core. These ducts are formed by inserting suit able spacing strips, which have not been illustrated, between the coils, the casing and the core. in the manner well understood by those skilled in the art, so that these por tions of the transformer will be as shown in 4. WVith this construction, the oil will circulate both through the coils and through the spaces between the core and the casing which incloses the coils of each group, thus independently ventilating the coils and the core. From Fig. 3 it is plain that the oil drawn up by the pump will be caused to circulate downwardly throu h the outside compartment around the outer casing 8 and ing coils 18, through which cooling liquid is' forced in any suitable manner; the terminals of said cooling coils being shown at 19, projecting through the side of .the base 6. It is thus apparent that the oil in its passage down through the outer compartment and in contact with said cooling coils will be deprived of its heat and will enter the lower end of the casing 8 at a much lower temperature than when it was delivered from the pump. 'The inner casing 7 compels the cool oil to flow up through the ventilating ducts between the coils and adjacent to the core of the transformer. I prefer to make the casing 7 with apertures 31 which may be formed as shown, or in any other suitable manner, so as to permit oil to flow up along the outside of the core through the apertures and into the casing 7 and thus cool the outside of the core. The arrangement of the casing 7 cuts off any tendency on the part of the pump to draw oil from the upper art of the space between the two casings 7 and 8 and thus insures a forced circulation of oil around the cooling oil in the outer chamber a and thence through the ventilating ducts in the transformer.

In the upper part of the inner casing is an opening 20 controlled by a gate or valve 21, and a similar opening 22 is made in the outer casing, registering with the opening 20, and controlled by the gate 23. Both gates are conveniently operated by a common handle 24, and if desired, there may be two sets of such gates, one on each side of the transformer, as shown in Fig. 3. Preferably these gates are only used in case the circulating pump gets out of order, or cannot be installed; the openings of said gates afi'ord exits for the heated oil from the upper part of the two casings to the cooling compartment surrounding them, so that a natural circulation will be set up. Of course, when the pump is in action, these gates are kept closed.

While I have described a preferred embodiment of my invention, I do not limit myself to this embodiment, but seek in the appended claims to cover all embodiments which will be obvious to those skilled in the art and will not depart from the scope of. my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. The combination with a transformer, of a tank having an outer compartment and an inner compartment, the latter containing the transformer liquid in said compartments,

rounding the core and windings, a tank surrounding said casing and forming a cooling compartment between them, liquid in the casing and the compartment, a cooling coil in said compartment, and means for trans ferring liquid from inside the casing to the cooling compartment.

4. The combination with a transformer, of a casing surrounding the same, a tank surrounding said casing and forming between them a compartment, oil in the casing and the compartment, a cooling coil in said compartment, and apump for sucking oil from the casing and delivering it into the compartment.

5. The combination with a transformer, of a casing surrounding the same and having openings at its lower end, a tank surrounding said casing, oil in the casing and the space between the casing and the tank, a cooling coil in the space between the casing and the tank, and means for transferring oil from the casing to said space.

6. The combination with a transformer, of a casing surrounding the same and having openings at its lower end, an inner casing fitting the upper part of the transformer, a tank surrounding the outer casing and forming therewith a cooling compartment, oil. in the casing and the compartment,

a cooling coil in said compartment, and means for producing a circulatlon of 011 from the inner casing to the cooling compartment and back again.

7. The combination with a transformer, of a casing surrounding the same and having openings at its lower end,-an inner casing fitting the upper part of said transformer, a tank surrounding the outer casing and forming therewith a cooling compartment, oil in the casing and the compartment, a cooling coil in said compartment, and a pump mounted on the transformer cover and taking oil from the top of the inner casing and delivering it to the top of the cooling compartment. I

8. The combination with a transformer, of a casing surrounding the same and having one or more openings in its lower end and also near its upper end, a gate controlling the upper openings, a tank surrounding said casing, and a cooling coil in the space between said casing and the tank.

9. The combination with an inclosing tank comprising two communicating chambers and containing a liquid, an electrical device submerged in said liquid and provided with ventilating ducts, and a cooling means disposed in the liquid in one of said chambers, of means for producing a forced circulation of liquid from the chamber containing the cooling means into the other'chamber and into the first chamber.

10. The combination with a transformer having ventilating ducts, a fluid-containin tank therefor, and acooling coil dispose Within the tank, of means for produc ng a forced circulation of fluid around the cool-e ing coil and through the ventilating ducts in the transformer. 11. The combination with a transformer, of a tank having an outer cooling compartment and an inner compartment containing the transformer, a liquid in said compartments, and means for suckin the liquid from one compartment and de ivering it to the other.

'12. The combination of a transformer, a tank surrounding said transformer, a casing inolosing said tank, oil inclosed in said tank and said casing, a pump, a ipe between said pump and said tank, anot or pipe between said casing and said pump, means -located between said casing and said tank for cooling said oil, said pump for maintaining a continual circulation of oil through one of said pipes thr0ugh the transformer structure back through the other pipe to said pump.

13. The combination of a transformer, a tank containing said transformer, an insulating fluid in said tank, a partition having openings at its upper and lower portions and located between said transformer and tank to establish a circulating path for said insulating fluid, and means in said circulatin'g'path for cooling the insulating fluid.

14. The combination of a transformer, a tank containing said transformer, arr-insulating fluid in said tank, a member, having openin s, located between said tankfand said trans ormer to establish a circulating pathfor said insulating fluid and means in said circulating path for cooling the insulating fluid.

15. The combination of a transformer, a tank containing said transformer, an insulating fluid in said tank, a partition having openings at its upper and lower portions and located between said tank and transformer to establish a circulating path for the insulating fluid between said tank and partition, and means located between said partition and tank for cooling said insulating fluid.

' 16. The combination of a transformer, two fluid containing tanks of different diameters surrounding said transformer, a cooling fluid and means between said tanks and supplied with said cooling fluid for from thence, through said ventilating ducts, h

cooling the fluid between tanks.

17. The combination of a transformer, a tank containing said transformer, an insulating fluid adapted to circulate therein, a baflie between said transformer and casing and having openings in its upper and lower portions, a pipe located between said battle and said casin and means supplying a fipe diium througfl said pipe for cooling said 18. The combination of a transformer, a tank containing said transformer, an insu lating fluid therein, a member, having openings, located in said tank to establish a circulating path for said insulatin fluid from the central part.of said tank, tirough said member, between said tank and member,

and through another opening to the central portion ofsaid tank, and cooling means for said insulating fluid between said tank and member,

19. The combination of a transformer, a tank containing said transformer, an insulating fluid in said tank, a member, hav ing openings, located in said tank to establish a circulating path for said insulating fluid from the central part of said tank through said member, between said tank and member, and through another opening to the central portion of said tank, an cooling means for said insulating fluid between said tank and member.

20. The combination with a transformer, of a tank having an outer cooling compartment and, connected therewith at the top and bottom, an inner compartment containing the transformer, and liquid in said com partments.

21-. The combination with a transformer,-

of a casing surrounding the transformer, a.

tank surrounding said casing and providing a cooling compartment between them, liquid in the casing and thecompartment and-a cooling coil in the compartment.

In witness whereof, I have hereunto set my hand this 20th day of April, 1910.

FRANK C. GREEN. Witnesses:

MARJORIE I. HALPIN, JOHN SnLENNox. 

